Any discussion of the background art throughout the specification should in no way be considered as an admission that such art is widely known or forms part of common general knowledge in the field.
Known protection devices have been primarily developed for TN electrical distribution systems and require a well-established and common earth connection to function correctly and safely. Most commercially available protection devices are not suitable for use in an IT electrical distribution system.
Protection devices that are available for use in an IT electrical distribution system are often complex and expensive to implement, and are only economic for use in high-end deployments.